Coming Soon to the Southwest: The Age of Thirst

The western United States could soon face the greatest water crisis in the history of civilization.

While that Arizona-California relationship guarantees full employment for battalions of water lawyers, a far bigger problem looms: climate change. Models for the Southwest have been predicting a 4º C (7.2º F) increase in mean temperature by century's end, and events seem to be outpacing the predictions.

We have already experienced close to 1º C of that increase, which accounts, at least in part, for last summer's colossal fires and record-setting temperatures—and it's now clear that we're just getting started.

The simple rule of thumb for climate change is that wet places will get wetter and dry places drier. One reason the dry places will dry is that higher temperatures mean more evaporation. In other words, there will be ever less water in the rivers that keep the region's cities (and much else) alive. Modeling already suggests that by mid-century surface stream-flow will decline by 10 to 30 percent.

Independent studies at the Scripps Oceanographic Institute in California and the University of Colorado evaluated the viability of Lake Mead and eventually arrived at similar conclusions: After about 2026, the risk of "failure" at Lake Mead, according to a member of the Colorado group, "just skyrockets." Failure in this context would mean water levels lower than the dam's lowest intake, no water heading downstream, and the lake becoming a "dead pool."

If—perhaps "when" is the more appropriate word—that happens, California's Colorado River Aqueduct, which supplies water to Los Angeles, San Diego, and the All-American Canal, which sustains the Imperial and Coachella Valleys, will go just as dry as the Central Arizona Project aqueduct. Meanwhile, if climate change is affecting the Colorado River's watershed that harshly, it will undoubtedly also be hitting the Sierra Nevada mountain range.

The aptly named Lester Snow, a recent director of California's Department of Water Resources, understood this. His future water planning assumed a 40 percent decline in runoff from the Sierras, which feeds the California Aqueduct. None of his contemplated scenarios were happy ones. The Colorado River Aqueduct and the California Aqueduct make the urban conglomerations of southern California possible. If both fail at once, the result will be, as promised, the greatest water crisis in the history of civilization.

Only Patricia Mulroy has an endgame strategy for the demise of Lake Mead. The Southern Nevada Water Authority is, even now, tunneling under the lake to install the equivalent of a bathtub drain at close to its lowest point. At a cost of more than $800 million, it will drain the dregs of Lake Mead for Las Vegas.

A horse killed in a February wildfire in Texas. 2011 was Texas' worst fire year on record. agrilifetoday/FlickrAdmittedly, water quality will be a problem, as the dead pool will concentrate pollutants. The good news, according to the standard joke among those who chronicle Sin City's improbable history, is that the hard-partying residents and over-stimulated tourists who sip from Lake Mead's last waters will no longer need to purchase anti-depressants. They'll get all the Zoloft and Xanax they need from their tap water.

And only now do we arrive at the third act of this expanding tragedy.

TheAge of Thirst: Act III

Those who believe in American exceptionalism hold that the historical patterns shaping the fate of other empires and nations don't apply to the United States. Be that as it may, we are certainly on track to test whether the US is similarly inoculated against the patterns of environmental history.

Because tree rings record growing conditions year by year, the people who study them have been able to reconstruct climate over very long spans of time. One of their biggest discoveries is that droughts more severe and far longer than anything known in recent centuries have occurred repeatedly in the American Southwest. The droughts of the Dust Bowl in the 1930s, of the 1950s, and of the period from 1998 to 2004 are remembered in the region, yet none lasted a full decade.

By contrast, the drought that brought the Chaco Canyon-centered civilization of the ancestral Puebloans, or Anasazi, to its knees in the 12th century lasted more than 30 years. The one that finished off Mesa Verdean culture in the 13th century was similarly a "megadrought."

Jonathan Overpeck, a climate scientist at the University of Arizona who played a major role in the Nobel Prize-winning work of the Intergovernmental Panel on Climate Change, tells me that the prospect of 130° F days in Phoenix worries him far less than the prospect of decades of acute dryness. "If anything is scary, the scariest is that we could trip across a transition into a megadrought," he says. "You can probably bet your house that, unless we do something about these greenhouse gas emissions, the megadroughts of the future are going to be a lot hotter than the ones of the past."

Other scientists believe that the Southwest is already making the transition to a "new climatology," a new normal that will at least bring to mind the aridity of the Dust Bowl years. Richard Seager of Columbia University, for instance, suggests that "the cycle of natural dry periods and wet periods will continue, but…around a mean that gets drier. So the depths—the dry parts of the naturally occurring droughts—will be drier than we're used to, and the wet parts won't be as wet."

Drought affects people differently from other disasters. After something terrible happens—tornados, earthquakes, hurricanes—people regularly come together in memorable ways, rising above the things that divide them. In a drought, however, what is terrible is that nothing happens. By the time you know you're in one, you've already had an extended opportunity to meditate on the shortcomings of your neighbors. You wait for what does not arrive. You thirst. You never experience the rush of compassion that helps you behave well. Drought brings out the worst in us.

After the Chacoan drought, corn-farming ancestral Puebloans still remained in the Four Corners area of the Southwest. They hung on, even if at lower population densities. After the Mesa Verdean drought, everybody left.

By the number of smashed crania and other broken bones in the ruins of the region's beautiful stone villages, archaeologists judge that the aridifying world of the Mesa Verdeans was fatally afflicted by violence. Warfare and societal breakdown, evidently driven by the changing climate, helped end that culture.

So it matters what we do. Within the limits imposed by the environment, the history we make is contingent, not fated. But we are not exactly off to a good start in dealing with the challenges ahead. The problem of water consumption in the Southwest is remarkably similar to the problem of greenhouse gas pollution. First, people haggle to exhaustion over the need to take action; then, they haggle over inadequate and largely symbolic reductions. For a host of well-considered, eminently understandable, and ultimately erroneous reasons, inaction becomes the main achievement. For this drama, think Hamlet. Or if the lobbyists who argue for business as usual out west and in Congress spring to mind first, think Iago.

We know at least one big thing about how this particular tragedy will turn out: The so-called civilization of the Southwest will not survive the present century, not at its present scale anyway. The question yet to be answered is how much it will have to shrink, and at what cost. Stay tuned. It will be one of the greatest, if grimmest, shows on Earth.

William deBuys is the author of seven books, including the just published A Great Aridness:Climate Change and the Future of the American Southwest (a Pulitzer Prize finalist), and The Walk (an excerpt of which won a Pushcart Prize). He has long been involved in environmental affairs in the Southwest, including service as founding chairman of the Valles Caldera Trust, which administers the 87,000-acre Valles Caldera National Preserve in New Mexico. To listen to Timothy MacBain's latest Tomcast audio interview in which deBuys discusses the water politics of the American West click here, or download it to your iPod here. To stay on top of important articles like these, sign up to receive the latest updates from TomDispatch.comhere.

William deBuys is the author of seven books, including the just published A Great Aridness: Climate Change and the Future of the American Southwest (a Pulitzer Prize finalist), and The Walk (an excerpt of which won a Pushcart Prize).